Wood-pulp digester.



J. G. W. STANLEY.

WOOD PULP DIGESTER.

APPLICATION FILED 8EPT.25,1911.

1,061,767. Pa ented May13,1913.

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can inc- 1 ES WILLIAM STEY, 01F SAN 1ilE'tJhN'fJIlTSCO, CALIFORNIA,ASSIGNOE, BY

DIEEGT AND MESNE ASSIGNMEIIIS, TO STANLEY lPAlPER FIBREBOMZPANY, OFJSAN.FMNCISCO, CALIFORNIA, A CORPORATION OF ARIZONA.

WQOID-PULP DIGESTEB.

Specification of Letters Eatent.

Patented May 113, 1913.

- ing is a specificatlon.

This invention relates to a digester :ior the cooking of wood, straw,flax and other material for the manufacture of pulp.

The object of this invention is to provide adigester for cooking wood,straw, flax and other fibrousrnaterial in large quantities and toprovide a sim lo and e 'cient means'for drawing ofi the i uors in whichthe materials are cooked, an .for washing and cleansing the pulp so thatit will be entirely free from the chemical solutions employed in itsdigestion.

A further object is to provide means by which the digesting solution maybe con.-

densed and the chemicals contained therein separated therefrom. I

Other objects will appear hereinafter. The inventlon consists of theparts and the construction and combination of parts as hereinafter morefully described and claimed, having reference to the accompanyring?drawings, in Wh1Cl'1- igure 1 is .a vertical, sectional view of theinvention partly in elevation and partly in diagram. Fig. 2 is ahorizontal section on the line X-X of Fig. 1.

In the drawings, A represents the digester which consists ofiavertically disposed cylinder, of any suitable dimensions, and built ofsuch materials as to be able to carry a pressure of approximately from80 to 125 pounds. The cylinder A is preferably formed of steel and isrigidly mounted on a suitable framework 2, and is provided with adome-shaped head 3, having a feed opening formed therein which isclosable by means of a steam-tight door or manhole cover 4, of anysuitable description. The lower end of the cylinder A converges towardand terminates in a discharge opening which is closable by means of apeculiarly constructed ats '5 which is adapted to swing downwardi y whenit is desired to empty the cylinder A of the digested pulp as later,described. The gate 5 is formed with a hollow, hemispherical dome orspray hood 7 of a diameter slightly smaller than that of the dischargeopening of the cylinder A, which portion 7 is adapted to extend into thedischarge opening when the mate 5 is closed. The dome 7 is rovided witha series of perforations 6 w ich iormsteam communicating passagesbetween the interior of the dome 7 and the interior of the cylinder A,and whereby steam from a pipe 8 is admitted to the digester for thepurposes shortly to be described. Pipe 8 connects with a flexible hose 9leading to a pipe 10, which in turn connects with a steam 1pc 11 leadingfrom any suitable source 0 steam supply; a cut-oil valve 12 beingdisposed between the pipes 10 and 11 at any convenient point. An airpipe 13, leading from any suitable source of air supply, and a pipe.l4,leading from any suitable source of water sup 1y, intersect the pipe 10;and a pipe 15 lea s from the pi e 10 adjacent to the valve 12 and opensto tie interior of the c linder A adjacent to its upper end. Cut-ovalves 16 and 17 are disposed in the pipes 13 and 14 respectively. Acut-ofi' valve 18 is disposed in the pie 10 near its lower end and alike valve 19 15 disposed in the pipe 15 at a point adjacent to thecylinder A.

Mounted within the cylinder A, centrally thereof, is a verticallydisposed, perforated pipe 20, the upper end of which extends to a pointa short distance above the middle of the cylinder A and terminates in amanifold coupling 21; the lower end of the pipe 20 being a apted to beconnected with an 0 ening 22 leading through the wall' of the ome 7,when the gate 5 is closed.

A pipe 23 connects with the pipe 10 below '28. The lower end of the conenser coil 24 v plings 31 adjacent to the inner wall .of the cylinder A.Mounted in the couplings 31 are vertically disposed, perforated pipes 32which? end upwardly to a point a shortv distance below the dome 3 of thecylinder A and downwardly to a point a short distance above theconverging portion of the lower.

end ofthe cylinder.-

' The pipes 20 and 32 are supported in the cylinder A by means ofbrackets 33 which are mounted on the inner wall of the cylinder vand areconnected to the T-couplin'gs A cut-0d valve 34 is disposed in the pipe20 adjacent to its upper end, which valve is operated through a stem 35extending through a stug-box 36 in the wall of the cylinder A to theexterior "thereof and is provided with a hand-wheel on lts outer end bywhich the valve 34 may be opened or closed from the exterior of thecylinder A.

In the operation of the invention the gate 5 is closed'and the cylinderA is filled with wood or othermaterials to be treated, pre-- viouslyreduced to a suitable size, which is delivered to the interior of thecylinder A through the feed opening in the up er end thereof. Duringthis procedure t e cutofi valves 12, 16, 17 18, 19 and 25 are closed.-

A suitable-solution of caustic soda, sulfate of soda, or'otherappropriate substances, is

then delivered to the interior of the cylinder A in suficient quantitiesto practically submerge the materials previously placed therein. Thissolution may be tormed by mixing the dry powdered chemicals with thematerials to be treated and then admittingwater tojthe Interior'of thecylinder A through the pipes 14, 10 and 15 by opening the valves 17 and19. This being done, the cover 4: is,closed, whereupon the valves'l'?and 19 are-closed, and the valves 12, 18

and 34 are opened to admitof the passage of-steam to the interior of thecylinder A through the perforated bottom ordome 7, formed on the gate 5,and through the perforated .pipe sections 32 on the perforated standard20,- which are so arranged as to insure a thorough distribution of steamthroughout the mass contained in the cylinderA. When steam pressure inthe cylinder equals boiler pressure the valve 19 is opened. Thesteam isdelivered to the cylinder A at' a pressure ranging from 80. to 100pounds pressure and raises the temperature of the solution in thereservoir A to approximately the boiling point. When the cooking iscompleted, WlllCh may be any Loan-re? fibrous materials to pulp, usuallyabout eight hours, the valves 12, 18 and 19 are closed and the valve 25in the pipe 23 which leads to the condenser coil 24 is opened so as toallow the solution in the cylinder 'A to dram therethrough; the solutionpassing .outthrough the pipe 20 and the dome 7.

The liquor being drained from the'cylinder A, the valves 34 and 25 areclosed and water is delivered to the interior of the cylinder throughthe pipes 10 and 15 andsvalves 17 and 19, which water flows throughoutthe digested pulp and acts to wash and cool the pulp. Valves 17 and 19are then closed. Thevalves 16 and 18 are then opened to admit air to thecylinder through the dome 7 at the bottom closure. hen air pressure inthe cylinder A reaches approximately eighty pounds pressure per. squareinch, the

valve 18 is closed and the valve 25 is opened which allows thewash-water to flow to the tank 29 through the condenser coil 24. Thepressure of the air acts to force the liquids in the cylinder outthrough the pipe 20 and perforated dome- "to. the condenser '24, andthereby thoroughlyv cleanses and cools the pulp in the cylin er A. Thisbeing done, the valve 25 is closedand the gate 5" is opened so as topermit the digestedjand cleansed .pulp to discharge through the lowerend of the cylinder into a receiving hopper, of any suitabledescription,from whence it is removed for further treatment. The discharge of thepulp from the cylinder A is facilitated by directing the airpressureinto the upper end of the cylinder by opening the valve 19 so as to bearupon the pulp and force it downward; the valve'34 being closed toprevent the escape of the air through the pipe 20. The liquids drainedit it from the cylinder A contain the chemi- 29 and evaporating it. v

The thorough removal of the digesting solution from the pulp isimportant, inasmuch as it renders the pulp purer and at the same timeadmits of the chemicals therein being restored and makes possible theacquirement of by-products accumulated in the digesting process.

The gate 5 is here shown as mounted on an arm 37 on a shaft 38 on whicha toothed acorns? segment 39 is mounted. A worm 40 meshes with thesegment 39 and is adapted to be rotated, by means of a hand-wheel 41 soas to rock the shaft 38 and thereby swing the gate to open or close thedischarge opening in the lower end of the cylinder A. 'Bolts 42, pivotedon the cylinder,

- are adapted to pass between lugs on the periphery of the gate 5 whenthe latter is closed, and nuts 43 are screwed on the lower end of thebolts to securely clamp the gate 5 in its closed position.

' An important feature of this invention resides in the means forintroducing air under pressure to the interior of the container bothat'its upper and lower ends. In the latter instance it acts to agitatethe pulp to perwit the wash-water to percolate throughout the mass andthereby insures a thorough cleansing action taking place. This alsoserves to rapidlg cool the (pulp so that it may be readily Iandled an.worked immediately after its discharge from the container; the deliveryof the air to the upper end of the container acting, as beforementioned, to quickly force the cleansed pulp out oi the dischargeopening after the washwater has been drained therefrom Having thusdescribed my invention, what I claim and desire to secure by LettersPatent is 1. In a digester, the combination with a digesting tank'havinga perforated dome in the bottom thereof, of means for delivering steam,air and fluids under pressure to the upper end of the tank, means fordistributing steam, air and fluids through the interior of the tank,comprising a plurality of perforated, horizontally and verticallyarranged tubes connected together; a condenser, and means for deliveringsteam, air and fluids through the perforated dome in the bottom of thetank to said condenser.

2. A digester which includes a vertically disposed, cylindricalcontainer having a feed opening at its upper end and a discharge openmgat its lower end, a closure with a perforated dome for said dischargeopening, said dome consisting of a hemispherical, perforated hoodsmaller in diameter than the diameter or' said discharge opening, avertically disposed, perforated pipe in the container opening at itslower end to the interior oi the perforated dome, and a cut-0d valve insaid pipe operable from the exterior of the container.

3. A digester which includes a vertically disposed, cylindricalcontainer having a feed opening at its upper end and a dis chargeopening at its lower end, a closure with a perforated dome for saiddischarge opening, said dome consisting of a hemispherical, perforatedhood smaller in diameter than the diameter of said discharge opening, avertically disposed, perforated pipe in the container opening at itslower end to the interior of the perforated dome, a cutofi' valve insaid pipe operable from the exterior of the container, radial pipesleading from the upper end of said perforated pipc above said valve, anda vertically disposed, perforated pipe connecting with the outer end ofeach of said radial pipes.

at. A digester consisting of a container having a teed opening at itsupper end and a discharge 0 ening at its lower end, closures for saiopenings and a perforated partition plate at the lower end of thecontainer and forming with said bottom closure 21 fluid chamber which isin communication through said perforations with the container and mcommunication with a source of steam pressure sup ly and also in communication with the discharge for the liquid, said partition plate having aperforated hollow column extending upwardly from it and means fordelivering air under pressure into the top of the container.

5. A di ester consisting of a container havin a eed opening at Its upperend and a disc arge o ening at its lower end, closures for sai openingsand a perforated partition late at the lower end of the container anforming with said bottom closure a fluid chamber which is incommunication through said perforations with .the container andincommunication with a source of steam pressure supply and also incommunication with the discharge for the liquid, said partition platehaving aperiorated hollow column extending u wardly from it, means fordelivering air un er pressure into the top of the container, said columnhaving perforated radial branches with vertical perforated hollowterminals, said chamber below the partition plate and column, branchesand terminals so constructed and arranged to afford a percolating systemfor the steam and fluid through the material undergoing digestion.

6. A di ester consistln of a container having a eed opening at its upperend and a discharge 0 ening at its lower end, closures for sai openingsand a perforated partition late at the lower end of the container andforming with said bottom closure a fluid chamber which is incommunication through said perforations with the container and incommunication with a source of steam pressure supply and also incommunication with the discharge for the liquid, said partition'platehaving a perforated hollow column extending upwardly from it, means fordelivering air under pressure into the top of the container, said columnhaving perforated radial branches with vertical perforated hollowterminals, said chamber below the partition plate and column, branchesand terminals soconstructed and arranged to afford a percolatmama ingsystem for the steam and fluid through my hand in the presm bf o s ubscrib" the; material dundergging digestign, and a, WMZHQSSQS. va vedispose in san column an operable & from outside the digester tointerrupt com- WILLIAM w 5 munication between said chamber below theWimesws:

partition plate and. saiol branches. JQHN H; E cm-.5

In testimamy WhQEGBQ]? I have hereunto set CHARLES EDELMAN, 1

